The glass test: rash and fever in a child
Press a clear glass against the rash and look through it. If the spots fade, keep watching your child and call your pediatrician if there is a fever. If the spots do NOT fade under pressure, call emergency services right away: it could be meningococcal disease.
How to do the glass test
- Take a clear glass with smooth sides.
- Press the side of the glass firmly against the rash.
- Look through the glass to see whether the spots fade and disappear under pressure.
| Result | What you see | What to do |
|---|---|---|
| Spots fade | they disappear under the glass | Watch your child. With a fever, call your pediatrician. |
| Spots do NOT fade | still visible through the glass | Call emergency services now |
Darker skin
A rash can be harder to see on darker skin. Check paler areas: the palms, the soles of the feet, inside the eyelids and the roof of the mouth.
Early on, the rash may still fade. If your child seems very unwell, is drowsy, has cold hands and feet or is getting worse quickly, call emergency services (911 in the US, 999 in the UK, 112 in the EU) whatever the glass test shows. Full list: warning signs in babies.
Fever thresholds by age, when to call emergency services, the glass test and space for your pediatrician’s number. One A4 page to print. Download the cheat sheet
Calm Parent
Warning signs and emergency info are always at hand in the app, together with the temperature history you can show your doctor. No ads, 14 days of Premium free.
Get it on Google PlaySources
- NHS, Meningitis: symptoms and the glass test (nhs.uk)
- Meningitis Research Foundation
This article is for information only and does not replace medical advice. If something worries you, contact a doctor. In an emergency, call your local emergency number.